Correlation between angular anisotropy and fragment mass in 15 MeV proton-induced fission of Th232

The angular distributions of 15 fission fragments were radiochemically obtained in the 15 MeV proton-induced fission of $^{232}\mathrm{Th}$. It was found that the angular anisotropies of symmetrically divided fission fragments were smaller than those of asymmetrically divided fragments. With the assumption of two kinds of saddle points, one leading to a symmetric mass division and the other to an asymmetric division, the observed angular anisotropies could be well reproduced.NUCLEAR REACTIONS, FISSION Angular distribution in 15 MeV proton-induced fission of $^{232}\mathrm{Th}$, Bohr's channel theory, two kinds of saddle point configurations, mass division.